This is due, in part, to contradictory reports on the effects of IFN-α on ex vivo cultured myeloma cells: some studies showed that IFN-α induces apoptosis and inhibits growth on myeloma cell lines [22], while other studies reported that IFN-α is a survival factor for human myeloma cells via upregulation of anti-apoptotic molecule Mcl-1 [23]. This evidence concerns the gene MCL1 and plasma cell myeloma.